Sputtering processes can be used to deposit a thin film layer on a substrate or disk. Such sputtering processes can bombard a sputter target with ions and the target becomes the source of the deposition material. Due to the ion bombardment, the atoms of the target deposition material are ejected from the target and deposited on the substrate or disk. As the atoms of the target deposition material are ejected, an erosion pattern is created on the target.
The target erosion pattern is largely dictated by a magnetic field of a magnet that is positioned at the back of the target. More specifically, the magnetic field from the magnet confines the electrons which are removed from the target to a certain area of the surface target at the active sputtering area (see, for example, FIG. 2c of U.S. Pat. No. 5,876,576). As the ions bombard and erode the target, annular grooves (also called a race track or an erosion track) are created in the target. The race track or erosion depth limits the effective life of the sputter target. More specifically, when the deepest point of the erosion track reaches the bottom of the target surface, the useful life of the target is over. Typically, 20% to 35% of the sputter target material, as measured by weight, has been consumed (utilization) and the remaining material is refined into powder to form new targets. As such, the wasted target material can be as high as 65% to 80%. Accordingly, an improved sputtering system that decreases the amount of target material wasted in the sputtering process is needed.